Chennai accounts for only 6% of TN’s rooftop solar capacity, finds study

CHENNAI: Even though Chennai’s electricity consumption accounts for nearly one-fourth of the State’s total consumption, the city accounts for a mere 6% of TN’s solar rooftop photovoltaic capacity due to the prevalence of multi-storey buildings and subsidised electricity tariff.

According to the Needs Assessment Report for Scaling Up Rooftop Solar in Chennai, the city has a cumulative rooftop solar capacity of 31 MW, which is only 5.6% of the state’s total rooftop capacity of 526 MW.

The report was prepared by the C40 Cities Climate Leadership Group, through its partners Center for Study of Science, Technology and Policy (CSTEP) and ASAR Social Impact Advisors. They conducted a comprehensive study to assess current barriers to rooftop solar adoption in Chennai and further develop a roadmap for RPTV adoption in the city.

The report attributed the slow adoption to the high prevalence of multi-storey buildings and multiple EB connections in the same building. “It’s also difficult to distribute the power generated by the rooftop solar systems between different connections due to the absence of a ‘group net metering’ regime in the State,” it said.

Among the different consumer categories, the domestic category has the highest rooftop share of 49% followed by the commercial category at 30%. Net metering is the predominant regime (56%) in the State as it promotes self-consumption.

The report found that the EB tariff structure has not been conducive to solar adoption by consumers. “The State government provides subsidised electricity to domestic consumers with bi-monthly consumption of less than 500 units. With low increases in retail tariffs and subsidised electricity for domestic consumers, there are low financial incentives for residents, particularly low and middle-income households, to switch from the status quo,” it said. “The policy requiring the use of expensive domestic solar panel than imported panels adds to the cost of setting up a rooftop system. The subsidies merely off-sets the additional expense, rather than providing a real financial incentive.”

An analysis to evaluate the impact of network charges and retail EB tariffs on the feasibility of rooftop solar adoption revealed that domestic consumers installing a 2-kW solar system would have accumulated savings of up to Rs 3.41 lakh after excluding network charges. However, with network charges, the savings decreased by 15% to Rs 2.87 lakh. The payback period for a domestic consumer stands at eight years, which extends to nine years once the network charges are factored in.

“The gap analysis revealed a multifaceted set of barriers that impede the scaling up of rooftop solar systems in Chennai. Institutional gaps such as non-compliance post-certification and delays in net metering connections undermine the scalability of rooftop systems,” the report said